rexxars/vinmonopolet

const through2 = require('through2')

module.exports = function () {
  return through2(symmetricLine)
}

function symmetricLine(chunk, enc, callback) {
  let numQuotes = 0
  let lastPos

  // Look for quote (") character
  for (let i = 0; i < chunk.length; i++) {
    if (chunk[i] !== 34) {
      continue
    }

    // When encountering "double quotes" (""), skip ahead
    if (chunk[i + 1] === 34) {
      i++
      continue
    }

    // When encountering a single quote character, record the number of times
    // it occurs and the last position it was found at
    numQuotes++
    lastPos = i
  }

  // If we have an odd number of quote characters on a line (we're assuming
  // each chunk here is a line), replace the last single quote character found
  // with a space
  if (numQuotes % 2 !== 0) {
    chunk[lastPos] = 32
  }

  // Push the chunk back onto the other end of the stream. If the buffer is empty,
  // we don't want to add a newline (doesn't play well with csv-parser etc)
  this.push(chunk.length ? `${chunk}\n` : chunk)
  callback()
}